The present application is a continuation in part of my allowed copending application Ser. No. 161,851 filed June 23, 1980.
TECHNICAL FIELD
The present invention relates to a system for attaching a ski boot to a ski in such manner that good control of the skis will be had during down hill runs without impeding natural foot and leg movement during cross country skiing.
BACKGROUND OF THE INVENTION
During down hill skiing, the skis for the most part are kept beneath the body with the feet flat against the skis. During down hill skiing there must be a minimum of relative movement between the ski boot and the skis, so that the skis will turn laterally with the foot, and so that the skis will be held flat against the foot should the skis leave the ground. It goes without saying of course that there must be no front to rear slippage during any such movements.
In cross country skiing, the skis are alternately moved from a position behind the body to a position forward of the body similar to the movement which occurs during walking. During such movement the heel will be flat against the ski when it is forward of the body, and will lift off of the ski as it moves rearwardly of the body.
In one type of commonly used cross country ski binding, the toe of the boot is clamped to the ski in a manner permitting the boot to flex at the ball of the foot and the heel to lift off of the ski. These clamps usually, after a period of time, permit sufficient relative rotation between the boot and ski to result in poor lateral and or vertical control of the ski.
In another type of commonly used cross country ski binding, the toe of the boot is strapped to the ski; and with such an arrangement, the straps gradually flex and yield to permit a relative rotation that may result in even poorer ski control than is provided by the above described clamp arrangement.
I am aware of a prior art patent that teaches a vertical plate on the ski for abutment by the rear of the boot to prevent relative longitudinal movement between the boot and ski. I am further aware that it teaches locking means between such a rear plate and the rear of the boot; so that when the skier approaches a down hill run, he can lock the ski and boot together. This and other arrangements with which I am aware suffer from a number of deficiencies, such as trapping snow against the vertical heel plate which is then compacted as the heel comes down onto the ski during cross country skiing. This compacted snow must be removed periodically to allow proper foot movement during cross country skiing, and must also be removed before the boot can be locked onto the ski for down hill skiing. In addition, the mechanisms of which I am aware must be locked and unlocked anytime a transition is made between down hill and cross country skiing.
An object of the present invention is the provision of a new and improved system for attaching skis to ski boots in such manner that unimpaired leg movement is had during cross country skiing and good lateral control is had during down hill skiing.
A further object of the invention is the provision of a new and improved system of the above described type wherein the problem of snow accumulation between the boot and ski is greatly minimized.
A further object of the invention is the provision of a new and improved system of the above described type wherein transition between down hill and cross country skiing can be made without unlocking the ski from the boot.
A still further object of the invention is the provision of a new and improved system of the above described type wherein the boot and ski can be locked together to completely prevent compaction of snow between the boot and ski when snow conditions are such that compaction can be prevented in no other way.
Further objects and advantages of the invention will become apparent to those skilled in the art to which the invention relates from the following description of the preferred embodiments described with reference to the accompanying drawing forming a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an oblique view of a ski and ski boot attachment system embodying principles of the present invention, and showing the ski boot flexed at the ball of the foot as occurs when the boot is behind the body during cross country skiing.
FIG. 2 is a rear view of the ski boot shown in FIG. 1.
FIG. 3 is a plan view of the heel plate shown in FIG. 1.
FIG. 4 is a rear view of the ski boot and heel plate in a position where the boot is about to engage the heel plate.
FIG. 5 is a view similar to FIG. 4 but showing the heel against the heel plate as occurs during down hill skiing.
FIG. 6 is an oblique view similar to FIG. 1 but showing another embodiment of the invention.
FIG. 7 is an oblique bottom view of the ski boot shown in FIG. 6.
FIG. 8 is a rear view of the ski boot and heel plate of the embodiment of FIGS. 6 and 7 in a position where the boot is about to engage the heel plate.
FIG. 9 is a view similar to FIG. 8 but showing the heel against the heel plate as occurs during down hill skiing.
FIG. 10 is a cross sectional view taken approximately on the line 10--10 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to principles of the present invention, mechanism is provided for restraining longitudinal movement between a ski boot and a ski by means of a transverse pin and slot mechanism, the pin of which is received in vertical open ended slots. Either the pin or slot portion of the mechanism is located in the heel of a ski boot, and the cooperating portion of the mechanism is located on structure fixed to the ski. In the preferred embodiment, the heel of the ski boot is positioned between a pair of upstanding legs which laterally confine the heel when the heel bears against the ski. In the most preferred arrangement, the upstanding legs have vertical slots opening outwardly of their upper ends and a transverse pin is fixed to the heel of the boot. Such an arrangement permits the heel to move away from the ski with ease, and automatically centers the boot laterally and longitudinally each time the heel is brought down against the ski.
While the invention may be otherwise embodied, it is herein shown and described as embodied in a cooperating ski boot 10, and a heel plate 12 that is affixed to the top surface of a ski 14. The heel plate 12, that is shown in the drawing, comprises a flat center portion 16 and opposite end upstanding leg portions 18 and 20 which are spaced apart by a distance to snuggly confine the heel 22 of the ski boot 10. The upstanding leg portions 18 and 20 shown in the drawing, are formed by doubling back the metal strip from which they are made into an inverted U-shape with the free end 24 thereof positioned outwardly of the leg. The inverted U-shaped metal provides a spring detent which will later be described. The free ends 24 are preferably bowed outwardly at their center, as at 26, to provide a detent action. The inverted U-shaped legs are each provided with a vertical slot 28 that extends from their upper ends down past their bowed center section 26. Alternatively, the detent structure can be made as a separate unit which is riveted or spot welded to the upstanding legs 18 and 20.
The heel 22 of the ski boot 10 is provided with a transverse pin 30, the opposite ends of which are threaded as at 32 to receive fiber lock nuts 34. The fiber lock nuts 34 in effect provide adjustable stops which slid over the bowed center sections 26 of the upstanding legs 18 and 20. This provides a detent means which requires a vertical pull to lift the heel away from the ski. The nuts 34 can be adjusted free and clear of the legs 18 and 20 for normal cross country skiing. With such an adjustment, the heel will move down between the legs freely, and the ski boot will be centered longitudinally and laterally with each stride as the heel slides down between the legs and the transverse pin 30 slides into the slots 28. By tightening the nuts against the spring detents, the skis can be readied for down hill skiing. When the heel is brought down upon the heel plate a vertical pull will thereafter be necessary to produce separation. This force can be adjusted so that the weight of the ski will not cause the ski to separate from the boot when the ski is off of the ground. However, even when so adjusted, the heel can be pulled out of the detent mechanism and cross country skiing can be done without appreciable difficulty. With the mechanism so adjusted, cross country skiing can be accomplished by bringing the boot heel down to where the pin engages the detent mechanism, but does not ride past the detents 26. This is no great inconvience, since a cross country skier rarely puts his full weight onto the heel. However, even with such skiing action, the boots are centered during each stride in the same manner previously described. It will be seen that the mechanism above described also permits the absence of a vertical plate at the rear of the heel which would trap snow and cause its compaction by the heel. It will also be seen that the skier is ready for down hill by merely putting his weight on his heels, to push the pin 30 past the detents 26.
The embodiment shown in FIGS. 6 through 10 corresponds generally to the embodiment shown in FIGS. 1 through 5, but differs principally in that the bolt and nut detent mechanism is in two sections instead of one. Those portions of the embodiment shown in FIGS. 6 through 10 which correspond to similar portions of the embodiment shown in FIGS. 1 through 5 are designated by a like reference number characterized further in that a suffix "a" is affixed thereto.
In the embodiment shown in FIGS. 6 through 10, there are two threaded pins 40 and 42 which project through respective nuts 44 and 46 that are affixed to respective upstanding legs 18a and 20a. The outer ends of the threaded pins 40 and 42 have large diameter heads thereon whose periphery is serrated for finger gripping and threading of the pins through the legs 18a and 20a. The inner ends of the pins are adapted to engage the respective sides of the heel 22a immediately above the top edges of a U-shaped plate 48 that is affixed to the bottom of the heel 22a. As the pins 40 and 42 are tightened against the sides of the heel 22a, the upstanding legs 18a and 20a are sprung outwardly to provide more and more frictional force against the heel 22a.
In order for the plate 48 to be moved vertically past the ends of the pins 40 and 42, the upstanding legs 18a and 20a must be sprung outwardly by an additional amount. As the pins are progressively tightened against the heel 22a more and more vertical lifting force of the heel 22a is required to spring the legs apart and effect separation.
While it is not necessary in all instances, the pins 40 and 42 may be bored out as at 50 to accomodate internal spring biased detents. As best seen in FIG. 10, a detent ball 52 is provided in the end of the bore 50 and the ends of the pin 40 are turned over into a lip 54 to retain the ball. A coil spring 56 is positioned between the ball 52 and the inner end of the bore 50. Preferably, the spring 56 is sized so that it biases the ball against the lip 54 with a force that is slightly in excess of 1/2 of the weight of the rear end of the ski 14a. With both detent balls 52 above the top edge of the plate 48, the ski can be lifted from the ground under the action of the toe clamp 58 and ball detents 52. When detents 52 are provided, the upstanding legs are preferably stiff enough so that there is practically no deflection at this time. When it is desired that a greater force than the weight of the ski will be required for separation of the boot and ski, the pins 40 and 42 can be treated against the heel to force the detent ball inside of the bore 50. Once this has been done, the pins will be engaged by the top of plate 48 and a force greater than the weight of the ski will be required for separation. This force can be still further increased by increasing the projection of the pins 40 and 42 through their upstanding legs to increase the deflection and spring force of the upstanding legs. In the embodiment being described, the ski is provided with frustoconical projections 60 which are received in cylindrical openings 62 in the sole of the boot 10a inwardly of the toe clamp 58 to prevent longitudinal separation of the boot and ski.
While the invention has been described as releasably securing the heel of a ski boot to the ski, it can also be adapted to releasably secure the toe of the boot to the ski. It will be seen that construction of the present invention, when located forwardly of the ball of the foot, will locate the toe laterally and longitudinally of the ski and still permit unrestrained flexing at the ball.
While the heels of most ski boots are more narrow at the back than at the front, it is also within the contemplation of the present invention to make the sides of the heel generally parallel so as to minimize the trapping of snow beneath the heel.
While the invention has been described in considerable detail, I do not wish to be limited to the particular embodiments shown and described, and it is my intention to cover hereby all novel adaptations, modifications, and arrangements thereof which come within the practice of those skilled in the art and fall within the purview of the following claims.